A variety of different circumstances exist in which a person may be required to have a catheter inserted into their body for a medical procedure. Once such use for a catheter exists when a person needs to have an artificial airway, such as an endotracheal tube, placed in his or her respiratory system. During surgery, for instance, the artificial airway's primary function is to keep the patient's airway open so that adequate lung ventilation can be maintained during the surgical procedure. Alternatively, with many patients the endotracheal tube will remain in place to sustain mechanical ventilation for a prolonged period.
If an endotracheal tube is to be left in place for any substantial amount of time, it is critical that respiratory secretions be periodically removed. This is usually accomplished with the use of a respiratory suction catheter. As the suction catheter is withdrawn, a negative pressure may be applied to the interior of the catheter to draw mucus and other secretions from the respiratory system.
With conventional closed suction catheter assemblies, for example as the one set forth in U.S. Pat. No. 4,569,344 issued to Palmer, which is incorporated by reference herein in its entirety for all purposes, the catheter tube is enveloped by a protective sleeve. The catheter assembly includes a valve mechanism in communication with a vacuum source to control the suctioning process. At its distal or patient end, the closed suction catheter assembly is permanently attached to a manifold, connector, adaptor, or the like.
After the application of negative pressure, the catheter tube may be withdrawn from the artificial airway and, as the catheter tube is pulled back into the protective sleeve, a wiper or seal strips or scrapes a substantial portion of any mucus or secretions from the outside of the catheter tube. However, the distal tip portion of the catheter tube may not pass through the seal or wiper and thus any secretions or mucus on the distal end must be removed by other means. It is desirable to remove these secretions from the catheter tube in order to prevent contamination from infectious agents that may be present in the respiratory secretions. Patients using artificial airways often have compromised immune systems and are more susceptible to infectious agents.
Several mechanisms exist by which a catheter may be cleaned. For example, a lavage port may be included which enables the clinician to inject liquid into the area surrounding the tip of the catheter after it has been withdrawn from the patient's airway. When liquid is injected and suction is applied, the liquid helps to loosen and remove the secretions from the exterior of the catheter.
One significant problem with simply injecting liquid and applying suction is that the suction also causes a volume of respiratory air to be removed through the catheter. In a closed system, the air that is evacuated potentially disrupts the carefully controlled ventilation cycle and the amount of respiratory air available to the patient may be decreased as a result of catheter cleaning.
Prior respiratory suction catheter apparatuses have been developed in order to allow for cleaning of the distal tip of the catheter without substantially interrupting the airflow to the patient from the ventilator. U.S. Pat. No. 6,227,200 B1 issued to Crump et al., which is incorporated by reference herein in its entirety for all purposes, provides in one exemplary embodiment a flap valve that may be used to substantially isolate the distal end of the catheter from the patient's airway during cleaning. The flap valve also has an open position in which the catheter may be inserted through the manifold into the airway of the patient. Prior respiratory suction catheter apparatuses incorporate the flap valve and related structure such that these parts are permanently bonded to the manifold.
Although respiratory suction catheter apparatuses are provided with a cleaning mechanism in order to remove mucus and other infectious agents, it is often the case that the catheter itself needs to be regularly replaced in order to insure a more sterile respiratory circuit. Some manufacturers recommend replacement of the suction catheter every 24 hours with a new suction catheter. In the instance when the suction catheter needs to be replaced, the artificial airway structure, often a manifold, into which the flap valve and related parts are contained, and onto which the suction catheter is attached, is detached from the respiratory circuit. This detachment necessarily interferes with the supply of air to the patient, and increases the chance of ventilator associated complications. The new manifold having the catheter and valve is then attached to the ventilator circuit.
Therefore, there is a need in the art for a closed suction respiratory system that is capable of effectively cleaning the tip of a suction catheter without a resulting drop of ventilation air to the patient. Additionally, a need in the art exists in replacing a respiratory suction catheter apparatus with a new respiratory suction catheter apparatus without disconnecting the artificial airway structure from the ventilation circuit in order to prevent air loss to the patient and to lower the chance of imparting illness to the patient during the replacement procedure.